1 files changed, 36 insertions, 0 deletions
diff --git a/dom/bindings/CallbackInterface.cpp b/dom/bindings/CallbackInterface.cpp
new file mode 100644
index 000000000..55c1d4d7a
--- /dev/null
+++ b/dom/bindings/CallbackInterface.cpp
@@ -0,0 +1,36 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/CallbackInterface.h"
+#include "jsapi.h"
+#include "mozilla/dom/BindingUtils.h"
+#include "nsPrintfCString.h"
+
+namespace mozilla {
+namespace dom {
+
+bool
+CallbackInterface::GetCallableProperty(JSContext* cx, JS::Handle<jsid> aPropId,
+                                       JS::MutableHandle<JS::Value> aCallable)
+{
+  if (!JS_GetPropertyById(cx, CallbackKnownNotGray(), aPropId, aCallable)) {
+    return false;
+  }
+  if (!aCallable.isObject() ||
+      !JS::IsCallable(&aCallable.toObject())) {
+    char* propName =
+      JS_EncodeString(cx, JS_FORGET_STRING_FLATNESS(JSID_TO_FLAT_STRING(aPropId)));
+    nsPrintfCString description("Property '%s'", propName);
+    JS_free(cx, propName);
+    ThrowErrorMessage(cx, MSG_NOT_CALLABLE, description.get());
+    return false;
+  }
+
+  return true;
+}
+
+} // namespace dom
+} // namespace mozilla